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  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
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<script>
    o= {
      _year:2020,
      property: 'ssss'
    }

    Object.defineProperty(o,'year',{
      get: function () {
        return this._year
      }
    })
    console.log(o.year)
  </script>
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